Just to fill in the backstory why a man with over 40 years in darkrooms manages to fog film, here's the sorry tale.
I'd put a fresh 100 ft spool of Fomapan 100 in the bulk loader, slotted in a cassette, to discover the frame counter wasn't working. I wasn't sure whether this was because the film was slipping and hadn't loaded, or had loaded but not registered on the counter. Long story short, I shot the film but it wouldn't load on the developing spool. My first guess was the spool was damp - unlikely because I dry them scrupulously - so I carefully fold the loading bag sleeves and get myself another spool. Introduce the new spool through the sleeves and de-spool the "damp" spiral. At this point I realise there's a lot of film on the first spool, but re-load on the new spool anyway. The film doesn't fit. It wasn't a wet spool, it was too much film. Like 52 frames. Hmm..
Like most such tales it was a series of small errors and miscalculations that could have prevented the final cock-up, but at this point stupid kicked in. There were two films to be developed and I loaded the spools into the tank. Except there were now three spools in the bag, which I opened to discover a loaded spool of film. I'd put one loaded spool in the tank, and an empty spool, leaving one full spool in the now open changing bag. As luck would have it the 52 frame spool with long tail developed perfectly, the 36 exp spool was the one exposed to light.
I developed both rolls anyway, to find the second one unsurprisingly fogged. The surprise was the amount of original exposure showing through the fog, Hard to believe 1/250 sec can complete with 5 seconds of daylight. As I said, there was nothing important on the roll (I can remember) but thought it would be fun to see whether I could reduce fogging while leaving (some of) the original exposure intact. Also as a cautionary tale to newbies that time isn't always a teacher.
